Response of S. thermophilus LMD-9 to bacitracin: involvement of a BceRS/AB-like module and of the rhamnose-glucose polysaccharide synthesis pathway.

Streptococcus thermophilus is a lactic acid bacterium of major importance to the dairy industry as it is found in numerous cheeses and is one of the two bacterial species involved in the fermentation of yogurt. Bacterial two-component signal transduction systems (TCSs) play important roles in the process of bacterial environmental adaptation. S.

Characterization of Streptococcus thermophilus two-component systems: In silico analysis, functional analysis and expression of response regulator genes in pure or mixed culture with its yogurt partner, Lactobacillus delbrueckii subsp. bulgaricus.

The lactic acid bacterium Streptococcus thermophilus (S. thermophilus) is widely used in the dairy industry. As a food bacterium, it has to cope with changing environments such as milk, yogurt, as well as the digestive tract, after the product has been ingested.

Cell wall alpha1-3glucans induce the aggregation of germinating conidia of Aspergillus fumigatus.

The germination of Aspergillus fumigatus conidia can be divided into four stages: breaking of dormancy, isotropic swelling, establishment of cell polarity, and formation of a germ tube. Swelling of conidia is associated in liquid medium with a multi-cellular aggregation that produced large clumps of conidia. Conidial aggregation can be specifically prevented by the addition of alpha1-3glucanase.

[Evaluation of the bactericidal activity of chiral alkylammonium salts derived from N-benzoyl-amino acids with Escherichia coli and Bacillus cereus. II. -- Adsorption mechanism and interpretation (author's transl)].

By testing the antibacterial activity of new long-chained alkylammonium salts with organic asymmetric anions (N-benzoyl-amino-acids) we have been able to precise the kind of interaction that would take place between the microorganisms and the two groups of the surfactant molecule. Evidence for anion participation to the bactericidal activity appeared through kind and configuration of the amino acid. A mechanism is proposed, that takes into account, hydrophobic and ionic interactions with cation and anion participation.

[Evaluation of the bactericidal activity of chiral alkylammonium salts derived from N-benzoyl-amino acids with Escherichia coli and Bacillus cereus. I. -- Evaluation of the antibacterial activity (author's transl)].

Long-chained alkylammonium salts (C12 and C16) obtained from chiral N-benzoyl-amino acids were tested against Escherichia coli and Bacillus cereus, to evaluate their antibacterial efficacy. The bactericidal activity (MBC) determined by the membrane filtration technique and the bacteriostatic activity values suggested anionic group participation. The participation of the anion moiety, depended on nature and configuration of the amino acid.